1. Field of the Invention
The present invention relates to ceramic sheets and methods for producing the same. More particularly, the invention relates to piezoelectric/electrostrictive ceramic sheets.
2. Description of the Related Art
To date, piezoelectric ceramics whose properties are improved by aligning the orientations of tabular grains have been proposed. For example, a piezoelectric ceramic having crystal grains whose grain diameters in a width direction are larger than those in a thickness direction when observed in a cross section in the thickness direction has been proposed (refer to Patent Documents 1 and 2). Furthermore, piezoelectric ceramics whose piezoelectric properties are further improved by increasing the degree of orientation of a specific crystal plane in the crystals have been proposed. For example, a piezoelectric ceramic has been proposed, which is produced by forming a template material, whose grains are tabular and in which a specific crystal plane is grown, by firing at 1,000° C. to 1,100° C. for 5 hours, adding a matrix material and an additive to the template material, shaping the resulting mixture such that the template material is arranged in a predetermined direction, and sintering under heating the shaped body so that the matrix material is oriented (refer to Patent Documents 3 and 4).